MWCNTs and Cu_2O sensitized Ti-Fe_2O_3 photoanode for improved water splitting performance

摘要

Fe2O3 and Cu2O, both earth abundant materials are used in functionalizing Ti doped Fe2O3 photoanodes with Cu2O and MWCNTs for improving photoelectrochemical performance for hydrogen generation. Pristine Ti doped Fe2O3 are fabricated by spray pyrolysis deposition method on the conducting ITO coated glass substrate. Two different modifications are adopted to improve the photoelectrochemical performance of pristine sample by subsequent deposition of multi walled carbon nano tubes (MWCNTs) alone and also in combination with Cu2O. Better photoresponse in modified samples is attributed to increase in conductivity and promotion of electron transport to Fe2O3 layer due to presence of MWCNTs while formation of heterojunction also promotes charge transfer kinetics by effective separation of charge carriers. Offering high photocurrent density of 5.17 mA cm(-2) at 1 V vs SCE, high open circuit voltage (V-oc), least resistance, higher negative flat band potential (V-fb), Ti-Fe2O3/(MWCNTs + Cu2O), emerges as the most photoactive sample. High applied bias photon to current conversion efficiency (ABPE) value of 4.6% is obtained for the modified sample against 0.07% ABPE for Ti-Fe2O3 photoanodes. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.